1. Field
The following description relates to an apparatus and method of estimating a Direction of Arrival (DOA) receiving a wideband signal, and more particularly, to an apparatus and method of estimating a DOA of the wideband signal using a fast Fourier transform (FFT).
2. Description of Related Art
In recent years, business meeting-related electronic devices and small sized-home electronic devices such as entertainment devices or video games have been gaining popularity. Accordingly, in order to automatically track an active speaker in video conference or an object, a Direction of Arrival (DOA) estimation technique is combined in a Human Computer Interface (HCI), and thereby the HCI is more user-friendly and practical. Accordingly, the DOA estimation has been extensively studied in radar, sensor networks, and speech communication systems.
A widely used DOA estimation method may be a multiple signal classification (MUSIC) method, which performs narrow band signal DOA detection. In order to obtain a DOA of a wideband signal, a method to correct and improve a MUSIC technique originally used in the narrowband signal is needed, and a method in which the DOA and a source direction of the object are obtained by decomposing the wideband signal into multiple frequency bins, and then applying the narrowband algorithm may be used.
In a DOA estimation using a sensor array, in response to an inter-sensor spacing being significantly increased, a source not existing practically may appear to exist, and this is referred to as a spatial aliasing. Accordingly, to avoid the spatial aliasing, the maximal inter-sensor spacing should be less than a half-wavelength of a received signal. However, the DOA may not be accurately estimated with respect to a signal received from a long distance when the inter-sensor spacing is relatively reduced, and thus a large number of sensors may be used as an alternative solution.
Accordingly, a DOA resolution may be proportional to a maximal length of an aperture of the sensor array. Thus, where the above two described conditions are applied in the MUSIC, a greater number of sensors may be required. Since most studies related with the DOA of the wideband signal are based on a high resolution method such as a conventional MUSIC, a number of sensors may be increased, and a computation may become more complex.